Log Message:
Update to 2.21

Upstream changes:
version 2.21: Fri 28 May 12:01:00 CEST 2021

        Changes:
        - application/octet-stream is better for .dat [issue #11, Даша \ 
Федорова]
        - add video/webm which Google forgot to register [issue #12, Brent Laabs]
        - add image/webp which Google registered too late [issue #12, Brent Laabs]

version 2.20: Thu 22 Apr 12:48:35 CEST 2021

        Fixes:
        - problems with PAUSE cause the previous release to show-up in
          the wrong location.  Let's hope this release solves it.

        Changes:
        - heif/heic/heifs/heics/hif fix [issue #9, Даша Федорова]
        - no 'and' and 'or' extensions [issue #9, Даша Федорова]
        - application/octet-stream is better for .bin [issue #10, Даша \ 
Федорова]

version 2.19: Fri 16 Apr 11:47:10 CEST 2021

        Improvements:
        - update with the newest data from IANA and Apache httpd

        Changes:
        - mp4 preference is video/mp4 [issue #5, Даша Федорова]
        - yt preference is video/vnd.youtube.yt [issue #6, Даша Федорова]
        - 3gp and 3gpp preference is video/3gpp [issue #7, Даша Федорова]

version 2.18: Wed  9 Dec 10:29:46 CET 2020

        Improvements:
        - update with newest data

        Changes:
        - Mojo 6.0 changed types() into mapping() [Dmitry Latin]
        - Mojo 7.94 adds experimental file_type()
        - Mojo 7.94 adds experimental content_type()